Garden Guests &pests
A boudoir for suitors, a trap to stock the larder and an offspring incubator – a web is truly amazing, writes LEONARD CRONIN
From termites that create elaborate subterranean homes to leaf-weaving ants and paper wasps that construct the multi-celled egg-chambers suspended from the eaves of our house, the engineering and design skills of some of our smallest garden creatures are a constant source of wonder.
One engineering masterpiece that literally stops me in my tracks is the web of the golden orb weaver. Suspended from trees up to 10m apart, the wheel-like web of one of our largest spiders shimmers with a golden hue in the early morning sun. Spanning more than 2m, this huge web is built to withstand high winds and storms, trapping large insects such as beetles and cicadas, and even microbats and small birds. All are subdued by the spider’s venom, wrapped in silk and sucked of their vital juices.
Backing away releases the sticky threads, and does minimal damage to the intricate construction. The owner, a female measuring 2.5cm, remains motionless at the hub, unperturbed by the intrusion. All summer long she has been growing, and is now ready to mate. Around the periphery of her web, glistening like dewdrops, tiny male spiders feast on small insects trapped by the sticky threads, awaiting an opportunity to copulate.
She usually ignores their presence, but now she is prepared to be distracted by brave individuals plucking at the web, signalling their willingness to approach her, despite the high probability of being eaten. Males accept their fate, instinctively aware that the extra food they provide allows her to lay more eggs, giving their genetic code a greater chance of survival. After mating, the female spins a single egg sac to protect her 300 to 1000 precious eggs until they hatch some two weeks later.
The tiny spiderlings produce fine silk threads that catch the wind, ballooning them away to distant sites.
Spiders are often considered to be dangerous and a nuisance but, with the notable exception of a handful of species, most are inoffensive and effective predators of insect pests, consuming mosquitoes, grasshoppers, aphids, and a host of garden-destroying bugs.
Len gardens in the Northern Rivers, New South Wales